Curing efficiency is the total system efficiency (barn plus burner plus heat exchanger) and bottom line that can be quantified in pounds of cured leaf per gallon of fuel consumed. These numbers may vary considerably even in the same barn over a curing season because they are affected by such factors as barn loading rates, stalk position, ambient conditions, the condition of the tobacco, and curing management. In order to obtain the highest curing efficiency and significantly reduce curing costs, all the energy saving strategies for bulk curing must be applied.
- Load the racks or boxes uniformly with quality tobacco.
- Maintain adequate airflow through the tobacco.
- Practice good curing management, especially ventilation control.
- Make sure your heating equipment and barn are energy efficient and well maintained.
Growers should target a seasonal average curing efficiency of 10 pounds of cured leaf per gallon of LP gas, especially if uisng box barns. This targeted ratio will vary slightly with natural gas or fuel oil due to the differences in energy content per unit of fuel. Typically, the ratio of pounds of cured leaf per gallon of fuel will be less for lower-stalk tobacco and increase with middle- and upper-stalk tobacco. Growers who do not contentiously apply the energy saving stratagies are almost certain to result in excessive energy consumption during curing. The energy efficient guidelines and other postharvest topics are discussed in more detail in the Flue-Cured Postharvest and System Efficiency Guide.